An unintended pregnancy often leads to a problematic decision for young women, and sometimes for their partners as well. Both options, abortion or teenage motherhood, have a big impact on their lives. Sexual health policies therefore strive to prevent teenage pregnancies. Studies on risk factors show multiple risk factors. This study explores the prehistories of teenage pregnancies in order to understand the connection between different risk factors in the life courses of young women who became pregnant before the age of 20. Different scenarios can be distinguished. In order to succeed in reducing unintended pregnancies among vulnerable groups, preventive measures should address these complex prehistories and not only promote contraception use.